Harriers went 2-0 up through Ed Williams and Joe Ironside but let their opponents back in, who eventually turned the game on it's head to win 3-2.
MacFarlane spoke to the club's website after the game and said his side gifted Stourbridge the win.
“Ultimately I’m really disappointed with the result, it’s a really sore one for us,” he said. “It’s a harsh lesson to make sure that we see games out.”
“We had total control of the football match and had the game won, and we just gifted them a way back into it.
“It’s a harsh lesson for our young defenders today - we were cruising at 2-0 and had numerous chances to put the game to bed.
“I’ll stand up to it and take the responsibility as that’s the manager’s job.
"But I have said to the group that we are all together, as we have been when we’ve been winning, it’s the same when we’re losing.